At the same time we raised the center of the roof, we were pulling the side walls together. We used 2 -20 foot tow straps to reach across the barn from wall to wall - almost.. Here you can see the 2 ton rated come-along coupled between the cables from one post to the 20 foot tow straps that run to the other side of the barn.

During the process of jacking up the roof, we were raising each jack 1/4 inch, then tightening the come-along then raising the jacks again, tightening the come along.

Eventually we raised the ridge 4 inches and pulled the side in 5 inches.